If you want to be truly good at either one of those things (to the level that the grandparent talks about where he's a "walking database"), you're going to do all sorts of things that are not particularly beneficial to your health.

Next time you meet a really dedicated snowboarder, have him do a couple deep knee bends and take a listen. If you ever meet me, have me show you my knuckles, which I can no longer straighten nor bend completely after 15 years of dedicated finger training for Rock Climbing. Watch me do a one-arm pullup, then laugh as I fail to run a mile because I'm not actually, in any normal sense of the word, in shape.

Pretty much all the hobies I mention above, and most you could think of, require you to specialize in ways that make them unsuitable training for the general case area in which they improve you. Just like Chess sorta makes you smarter and piano sorta makes you more dextrous, training for a sport just sorta makes you healthy. But mostly it makes you a better snowboarder, climber, etc.